Assembly of sheets stapled to a backing member,and associated methods of installation



June 23, 1970 J. D. LANGWELL- 3,516,687

ASSEMBLY OF SHEETS STAPLE D To A BACKING MEMBER, AND ASSOCIATED METHODSOF INSTALLATION Filed April 19, 1968 Wh ll 1 5 4 z FIG.2

INVENTOR. JOHN D. LANGWELL Fab;

ATTORNEYS United States Patent O ABSTRACT OF THE DISCLOSURE An assemblyof sheets mounted on a backing member by a loop staple having one legpassing through the sheets and the other leg passing through a plugwhich is held between the bridge of the staple and the backing member.

BACKGROUND OF THE INVENTION Field of the invention 1n1s inventionrelates to the installation of a staple to secure a plurality of sheetsagainst a backing member to form a pad from which the sheets areremovable by being torn from the staple.

Description of the prior art It is well known to employ staples tosecure a plurality of sheets to a backing member. It is also known toform the staple with a particular shape to enable the sheets to be looseon the staple and thereby be removable from the staple by being torntherefrom. Moreover, the shape is such as to keep the staple anchored tothe backing member after some sheets are removed. The requirement ofsuch special shapes for the staples complicates their manufacture andinstallation and greatly increases the cost of the assembly.

SUMMARY OF THE INVENTION An object of the invention is to provide astaple assembly of the above character in which the staple is ofstandard loop form and hence does not increase the cost of the assembly.

Another object of the invention is to provide suitable means, of aninexpensive nature, which can be installed together with the staple andbe eifective to keep the staple anchored to the backing member afterremoval of some sheets.

Another object of the invention is to provide a method of assembly ofsheets and staples to a backing member with the aforesaid means which issimple and reliable.

Yet another object of the invention is to employ a resilient plug in astaple assembly of the above type in order to utilize the resilience ofthe plug to enhance the anchoring of the staple to the backing memberafter some sheets have been removed.

In accordance with the invention, a staple body of loop form is securedto a backing member to hold a stack of thin sheets against the backingmember. One leg of the staple body passes through the sheet and isclinched to the backing member, and the other leg of the staple bodypasses through a plug and is also clinched to the backing member. Theplug is interposed between the backing member and a bridge of the staplebody joining the two legs, the plug serving to hold the staple bodyanchored to the backing member, particularly after removal of sheets.

Advantageously, the plug may be constituted of a flexible material whichis compressed between the staple body ice and the backing member. Thisensures the anchoring of the staple body to the backing member right upto the removal of the last sheets of the stack.

In further accordance with the invention, a method is provided for theassembly of the sheets to the backing member using staples and plugs ofthe type described hereinabove. According to this method, one leg of astaple body is passed through the stack of sheets and backing member andclinched against the backing member while simultaneously the other legof the staple body is passed through a plug and the backing member andclinched against the backing member.

The method is applicable to the successive installation of staplesthrough stacks of material on respective backing members to mass producepads in succession. In this respect plugs are fed in synchronizationwith stacks of sheets on respective backing members, and staples aredriven into the sheets, plugs and backing members to produce repeatednumbers of pads.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a padaccording to the invention;

FIG. 2 is a sectional view on enlarged scale taken along lines 2-2 inFIG. 1;

FIG. 3 is a plan view of a portion of a pad according to a modifiedversion of the invention;

FIG. 4 is a sectional view on enlarged scale taken along lines 4-4 inFIG. 3 g and FIG. 5 is a diagrammatic side elevation view of apparatusfor producing a stapled pad according to the invention.

DETAILED DESCRIPTION In FIG. 1 of the drawing there is seen a pad 1which includes a rigid backing member 2 constituted, for example ofcardboard or the like, and a stack of sheets 3 of flexible material,such as paper, mounted on the backing member by a pair of staples 4 atone edge of the stack. The sheets of the stack are removable from thepad by being torn from the staples.

In order to preserve the anchoring of the staples to the backing member,after removal of sheets from the stack, plugs 5 are employed. Withoutthe plugs 5, the staples 4 would be free to pivot with respect to thebacking member after some sheets 3 have been removed. As a consequence,the staples readily separate from the backing member under the actionof, and by the removal of the sheets. This frequently occurs afterremoval of only a relatively few sheets, and therefore the pad becomesdismantled and the major portion of the stack is unused.

The plugs 5 serve to anchor the staples to the backing member bypreventing the harmful pivoting movement of the staples with respect tothe backing member. In operation, the plugs act to hold the staples in afixed position on the backing member, thereby ensuring the permanentanchoring of the staples to the backing memher.

As seen in FIG. 2, each staple is constituted as a continuous length ofmaterial of loop form with two spaced leg portions -6 connected by abridge portion 7. One leg of the staple passes through the stack ofsheets 3 and is clinched to the backing member 2. The other leg of thestaple passes through the plug 5 and is clinched to the backing member.

It is important that the plug 5 have a relatively tight fit between thebridge portion 7 of the staple and the backing member 2. Without such afit, the staple will be free to wobble with respect to its backingmember, particularly when the sheets are torn from the staples and thisenlarges the holes in the backing member through which the staples pass.Eventually one of the legs of the staple will pull through the enlargedholes of the backing member and the connection of the staple to thebacking member will be destroyed.

In order to provide a tight fit of the plug 5, the inventioncontemplates several solutions. In a first, the plugs are relative rigidand have a height corresponding to the length of legs 6. Hence when theplugs are installed with the staple they will be tightly fitted inplace. However, this requires the need for plugs of different heightsfor the various heights of staples for different thickness pads. This isgenerally disadvantageous, since it requires maintaining a stock ofdifferent size plugs. Moreover, it is necessary to carefully distinguishthe plugs of differene sizes, since by casual inspection two adjacentsizes may appear to be similar. Different colors may be used fordifferent sized plugs but this increases their cost. Thus, thisembodiment will generally be used for staples of only one size.

It has been found that an effective tight fit of the plugs can beobtained by making the plugs of resilient material, such as rubber,plastic or the like, and compressing the plug between the bridge portion7 and the backing member 2. This not only results in a tight fit for theplug, but the resilience of the plug, and its compressed state in theassembly, insures a tight fit and consequent anchoring of the staple tothe backing member down to the removal of the last sheet of the stack.The resilient plug may be of suitable size, in its uninstalledcondition, as to be usable with a wide range of staple heights forvarious pad thicknesses. Thus, only one, or perhaps two, sizes of plugsare necessary for the entire range of pad thicknesses and stapleheights. Moreover, these two sizes of plugs will be obviously differentby visual inspection and hence the likelihood of installing plugs of thewrong size is remote.

As shown in FIGS. 1 and 2 the plugs are of cylindrical shape. This shapehas great value since the plugs require no angular orientation in theirinstallation. Moreover, such plugs have a wide bearing surface forresting on the backing member, and the bridge portions 7 lie fiat on theupper surfaces of the plugs. The diameter of the plugs must beconsiderably greater than the diameter of the wire of the staple and theratio of such diameters will be at least a value of 3 and generally muchhigher. Preferably, the plugs will bear against the edges of the sheets3, in the manner as shown in FIG. 3 for plugs a of a modified version.In this respect, it is to be understood that the plugs 5 may bearagainst the edges of sheets 3 even though shown spaced therefrom in FIG.2.

The plugs 5a in FIGS. 3 and 4 have a tubular shape and the staples passdiametrically therethrough. The shape of the plugs 5a promotes theirflexibility. As has been described hereinabove, it is preferred that oneend of the plug abut the edges of sheets as shown in FIG. 3. This aidsin maintaining the sheets in a fixed position on the pads and tends torelieve the load on the staple. The material of plug 5a is alsopreferably resilient and consequently this plug undergoes a flatteringdeformation upon installation and subsequent restoration which promotesthe pre-stress action on the staple.

It is preferable that the staple pierce the material of the plug when itis installed, and for this reason the plug material should be readilypierceable by the staple leg. The rubber and plastic materials, whichare preferred for their resilience, are also suited for being pierced bythe staple. Hence these materials are greatly advantageous. However, itis also possible for the plugs to be pre-formed with axial bores and forthe staple legs to pass through such bores.

FIG. 5 schematically shows the installation of staples for formation ofpads. In FIG. 5 are seen a staple head and an anvil 11 positionedtherebeneath. Backing members 2 each with a stack of sheets 3 thereonare fed in succession by a suitable mechanism (not shown) onto the anvil11 into a predetermined position beneath the head 10. A supply tube 12for a vertical stack of plugs 5 is positioned adjacent head 10. Areciprocally movable arm 13 operates in synchronization with themechanism which feeds the backing members and sheets to the head, suchthat the plugs are displaced into position on each backing member at alocation in alignment with the leg of its associated staple. The staplehead then drives a staple into the plug, sheets, and backing member toform a pad as seen in FIG. 5. The pad is removed from beneath the headby a suitable device (not shown) and the above described operation isrepeated successively to produce repeated numbers of pads.

Numerous modifications and variations of the disclosed embodiments ofthe invention will now be apparent to those skilled in the art withoutdeparting from the scope and spirit of the invention as defined by theappended claims.

Thus by way of example, a greater or lesser number of staples may beinstalled at the edge of each stack of sheets of each pad as dictated bythe size of the pad.

What is claimed is:

1. An assembly comprising a backing member, a staple body secured tosaid backing member for holding a stack of thin sheets of materialagainst said backing member such that the sheets of material areremovable by being torn from the staple body, said staple body beingconstituted as a continuous length of material of loop form with twospaced leg portions which penetrate said backing member and are securedthereto, and a bridge portion between the leg portions extending inspaced relation from the backing member, one of said leg portionspassing through the stack of sheets, and a plug engaged with the otherof the leg portions and extending between the bridge portion and thebacking member for anchoring the staple body to the backing member, saidplug serving to hold the staple body anchored to the backing memberafter removal of sheets.

2. An assembly as claimed in claim 1 wherein said plug is constituted ofa material in which said other leg of the staple body is pierceable.

3. An assembly as claimed in claim 2 wherein the plug material isflexible.

4. An assembly as claimed in claim 1 wherein said plug is of cylindricalshape and said other leg of the staple body passes axially therethrough.

5. An assembly as claimed in claim 1 wherein said plug is constituted offlexible material which is axially compressed between said bridgeportion and the backing member.

6. An assembly as claimed in claim 1 wherein said plug is of tubularshape and said other leg of the staple body passes diametricallytherethrough.

7. An assembly as claimed in claim 1 wherein said plug is in abutmentwith the stack of sheets.

8. An assembly as claimed in claim 1 wherein said plug has a borethrough which said other leg of the staple body passes.

References Cited UNITED STATES PATENTS 9/1932 Lawson 282-22 JEROMESCHNALL, Primary Examiner US. 01. X.R.

